


I Know What I'm Doing

by StarlightSystem



Series: Transcendence AU [7]
Category: Gravity Falls
Genre: Alternate Universe - Transcendence (Gravity Falls), Demon Instincts, Gen, Look at me I wrote a fight scene, Sibling drama, Unresolved Tension
Language: English
Status: Completed
Published: 2020-07-04
Updated: 2020-07-04
Packaged: 2021-03-05 03:55:49
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 4,034
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25068037
Author URL: https://archiveofourown.org/users/StarlightSystem/pseuds/StarlightSystem
Summary: A couple of years after the Transcendence, Mabel and Dipper are leading completely different lives, filled with mystery, heroism, and Dipper's burgeoning demonic powers. In general, they are closer than ever before, but a botched cultbashing mission reveals that not all is well between the twins.
Series: Transcendence AU [7]
Series URL: https://archiveofourown.org/series/1372192
Comments: 9
Kudos: 45
Collections: TAU Discord Recs





	I Know What I'm Doing

**Author's Note:**

> This takes place in the [Transcendence AU](https://transcendence-au.tumblr.com/)!

Bathed in the light of day, the two stars shined.

The forest glimmered with life, from the whispering water trickling through the rocks, to the dryads opening their eyes to welcome the morning. The forest was at peace, or at least, that’s what it wanted you to believe, as it was quite happy to pretend that in this place, this sprawling wilderness spooning a sleepy town, all was right with the world.

But, the slow, intermittent rumble in the ground belied the forest’s intentions. A distant roar, unlike that of any natural or unnatural beast, reverberated through the trees, and all the forest’s denizens fell quiet in anticipation.

For a moment, the silence was complete.

Then, the golf cart came screaming over the ridge, suspended in mid air for a brief few seconds before crashing down to the earth below. Undeterred, it coasted forward, swerving back and forth as the cart attempted to maneuver the rough terrain of the forest. Two figures were visible in the cart; one in the front, driving, and one in the back.

“Alcor, tree!” yelled a high-pitched voice.

The driver grunted and spun the steering wheel hard to the right. The cart skidded on the dirty path and upended on its left wheels mere inches away from the tree in question. Then it was down, wheels squealing as the cart took off again.

The driver looked to be a young man no more than 20 years old, and yet he was commanding the golf cart like he was 12. He was dressed oddly for a chase scene; a smart, black suit and coattails where a t-shirt and vest might have been more appropriate. His fluffy brown hair bristled in the breeze created by the rushing vehicle, unhindered by the top hat that was floating a few inches above his head. There was something deeply inhuman about him, but in the excitement of the moment it was hard to tell exactly what it was.

Maybe it was the wings. Maybe it was the gold-on-black eyes. Or maybe it was the aura of power radiating so strongly from him that it was almost visible to the naked eye.

The woman in the back seat could’ve been his sister but for the fact that she looked as human as they come. She was about the same age, had the same brown hair but longer and tied into a ponytail, and had a similar height and build, if a tad more muscular. She was dressed more reasonably for an excursion into the forest, clad in a red sweater with “I’M THE EVIL TWIN” printed on it. She leaned over the rim of the side of the cart, gripping a baseball bat of all things as if it was a sniper rifle. Despite her confident body language, she was betrayed by the look of terror on her face, in stark contrast to the obnoxious grin on the boy’s.

They were Alcor and Mizar, twin stars, and they were on the hunt for the most dangerous game: cultists.

Another quick turn, and their prey came back in view – a dark blue car with hooded figures poking out the windows. By all rights, a golf cart should not have been able to keep up with an actual car, but this car was too big, too clunky, and kept getting caught up on the features of the forest floor that the cart was able to coast right over. There might have also been a touch of magic at play, but who could tell for sure?

“They’re back!” Mizar shouted.

“I’ll take care of them,” Alcor replied, starting to stand up.

“Keep your pretty claws on the wheel, hot shot!” Mizar shot back. “I’ve got this!”

Alcor sat back down and grumbled to himself, but did as he was told. Mizar looked back at the cultists they were chasing and saw that one of them had drawn a gun and was pointing it at her.

Quick as a whistle, she gripped her baseball bat, aimed it at the cultist, and flicked her finger in midair, as if she was pulling a trigger. With a boom, a ray of rainbow light shot out of the end of the bat, causing it to recoil in Mizar’s hands. Her target saw the incoming spell and fumbled with their gun, but it was too late – the beam of light made its impact, and the hooded figure was gone. In their place floated a frog, who gave a stereotypical croak before falling to the forest floor. The transformation lasted only a minute, after which the assailant reverted to human, but by then their vehicle had left them far behind.

Unfortunately, the three other cultists hanging out the car windows were now also sporting guns. Mizar took aim at the one in the front passenger seat and fired again, but her shot completely missed thanks to the cart suddenly swerving to the left.

“Heck!” she swore, sort of. “Alcor, what are you _doing_ over there?”

“Driving responsibly!” he snarked back. “Just trying to get us there in one piece.”

Mizar rolled her eyes. “They’re firing at us!” she retorted. “Can you bring up a shield or something?”

Alcor grumbled to himself again, a bit louder this time, something that sounded suspiciously like “if we had just killed the cultists when we were back at the campsite then we wouldn’t be in this mess.” Mizar glared at the back of his head, which he seemed to detect, as he then added “Alright, here goes nothing.”

She turned around again just as she registered the sound of more gunfire. She gasped and hit the deck. “Any minute now, Ally!”

All she got in response was a grunt. She heard gunfire again, which was followed by a strange metallic drone. She looked up, and saw that there was a semi-transparent bubble wrapped around the golf cart. She stood up just in time to see a third barrage of bullets racing right at her. She flinched, but the bullets hit the bubble and bounced right off.

“Good job, bro-bro!” she exclaimed. The smile fell right off her face, however, when she turned around to see her brother, fists clutched at his temples, knees to his chest, and eyes shut. Her heart jumped into her throat as she looked past him and saw that the forest they had been tearing through abruptly stopped some 30 feet away, and that all there was left to welcome them was open air.

“Di- Alcor, the road!” she screamed, diving onto him to try to grab the wheel. He opened his eyes, confused, and the shield shattered around them, spraying bits of magic everywhere. They both yelped and fumbled for control of the steering wheel. Mizar tried to grab it from her brother’s wildly flapping hands, but one of his wings accidentally smacked her in the face, and she stumbled over the passenger chair into the back seat.

“Oh no, Mizar, I’m sorry!” he cried, looking away from the road again.

Mizar’s eyes grew wide, and she tried to speak, but no words would come. Alcor stared at her in confusion for a moment before the scream in his sister’s throat finally erupted, and the ground vanished from beneath them. Once again, the cart was airborne – however, this time, there was a lot further a distance for it to fall.

Alcor shut his eyes and clenched his fists against his temples again. Mizar shut her eyes too – whatever was about to happen probably wasn’t going to be pretty. Her brother had been getting better at his magic but… as evidenced by what had just happened with the shield, she couldn’t be 100% certain that they’d actually get out of this without getting hurt.

She heard the sound of squealing tires behind them, followed by slamming doors and gunshots. There was little to no chance that they’d be able to lay a round on the plummeting golf cart, but she couldn’t stand the sound of gunshots, not now when she was already stressed about the lack of ground beneath her. She started screaming again, just to drown it all out. She screamed and screamed and… suddenly a pair of clawed hands had grabbed her shoulders and was shaking her.

“Mizar! It’s okay! You can open your eyes!” came her brother’s voice.

Mizar opened her eyes. She was still in the golf cart, and, yep, she was still alive. The cart was sitting peacefully on the ground next to the cliff, no worse for wear. Alcor was sitting in front of her, panting. He sighed in relief when he saw her eyes open, and then his expression twisted into a slightly smug grin.

“Told ya I could handle tessering both of us and the golf cart at the same time,” he said.

Mizar just stared at him for a moment, jaw dropped. Then she grabbed her bat and softly bapped her brother on his head. Unlike him, she was not smiling.

“What was that?” she admonished.

The smile on Alcor’s face wavered. “What do you mean? I saved us.”

“No!” she retorted. “What were you doing driving the cart with your eyes shut? You literally drove us off the cliff!”

“I had to concentrate to conjure the shield!” he whined in response. “And who cares about the cliff when I have magic? You’re not gonna be in danger as long as I’m here.”

Mizar couldn’t help but notice the smug smile returning to her brother’s face for just a moment during that last sentence. She face-palmed.

“Bro-bro, I love you and all, but get your head out of your butt!” she yelled. Alcor looked taken aback by this, but she didn’t give him the opportunity to interrupt her. “You just said that making the shield was hard. What if you couldn’t blip us to the ground in time? I’d be toast!”

“Then I’d just grab you and float down-”

“Dipper, you’re not listening to me!”

Alcor froze at the sound of his true name. “Ma- Mizar, shh!” he hissed. He looked around, trying to feel out the presence of anyone who might have overheard them. The only noise was the gentle babbling of the brook, and the distant rat-a-tat-tat of a woodpecker. He sighed in relief, and looked back at his twin. “It’s not safe to use our real names when we’re on a job!”

Mizar pouted. “Well, I’m not talking to the great and powerful Dreambender right now, I’m talking to my dope brother who’s gotten so full of himself because of his magic that even I think he’s being careless! We might be okay now, but you still have to try and avoid getting into dangerous situations in the first place! And, in case you didn’t notice, by driving off the cliff, we lost the cult, which was the whole reason we’re out here!”

Alcor sniffed. “We should’ve just killed them back at the campsite.”

“We went through this, Ally McBeal, we let them live so they would lead us right to where they were keeping the human sacrifices!”

“Mizar, it’s fine, I’ll just use my omniscience to find them. We didn’t need to go through this.”

“Well, I guess it’s all my fault! Seriously Alcor, do you really want to go through an infodump right now?” Mizar asked, exasperated. She thought about the last time she’d stepped into the backyard and found her brother mid-infodump, and shivered. “I think they’re getting worse, bro-bro. I don’t know if you can handle that right now, especially when the cult could be sacrificing those kids any minute.”

Alcor sat on a log and shifted into full-on pouting mode. “I don’t always need to infodump to see things, Mizar. Their hideout could already be in my sphere of knowledge. And as a last resort, I’ll definitely be able to feel another demon in my territory,” (he said this with a glint in his eye) “and then we can tesser there and save the kids.”

Mizar sighed, and sat down next to her twin. “Al, that’s not the point,” she said, anger seeping out of her voice to be replaced with concern. “You’re getting so caught up in being a demon that you’re forgetting how to do things the normal way.”

Alcor’s stare fell, and he looked awkwardly at his shoes. Mizar kept going. “You’ve gotten used to being super cool and powerful and stuff, but you don’t really want to be a demon, right? I know it’s still you in there and that you like being a human and doing human things. So please, when we’re out hunting or cult-bashing or whatever, can you let the human part of you come out and play too?”

Alcor looked to be deep in thought, and then looked up at his sister.

“Mizar, I-” he started, but was cut off by the roar of an engine.

“You!” cried a familiar voice. The twins looked up and saw the car they were chasing earlier pulling into the clearing they were in. The speaker was one of the cultists that had been leading the chanting back at the campsite. Ten cultists tumbled out of the car, each clutching a weapon of some sort.

The twins jumped up in surprise. Mizar grabbed her bat and shifted into a power stance. Alcor poofed his wings out, bared his teeth, and let out a deafening snarl. The cultists staggered from the noise, but so did Mizar, who dropped her bat in the rush to cover her ears. She glared at her brother and ducked to pick up her bat.

“Why’d you come here?” Alcor bellowed, not waiting for his sister to get back into position. “Do you have a death wish?”

The cultists were disoriented, but rallied surprisingly quickly, shoving the speaker from earlier to the front of the group.

“Do your worst!” they yelled back, unsuccessfully trying to hide the fear in their voice. “We’re not going to let you take our base without a fight!”

“Base?” Mizar echoed, confused. She looked up at her brother, who had – again – shut his eyes and was spinning around. After a moment, he opened them again and pointed to a cave cut out in the cliff nearby.

“There’s fear radiating out of that cave over there,” he said, flatly.

“We found their base by complete accident,” Mizar whispered in awe.

Alcor swiveled to face his sister, face adorned with a shit-eating grin. “And we wouldn’t have found it if we hadn’t driven off the cliff.”

She glared at him again. “This is not the time for th- frick!” she started, and then yelped at the sudden pain in her arm. A bullet had just barely grazed her, cutting open the sweater and burning her skin. She jumped and turned back to the cult, who had taken advantage of the pair’s distraction and grabbed their weapons. Alcor turned too, and hissed.

“T̡͙h̞͔͞ͅa̟̮͔͓t̯’̼͔̮s̬͉͚̖̪̝͈͜ ̸̗̜̺I̼̞̘͕̯T̪!̵̪” he roared, flying up into the air and then dive-bombing onto one of their assailants.

Mizar groaned, and, baring her bat, ran at the cultist that had shot her. They fired again, and Mizar swung her bat, colliding with the bullet and sending it flying back at the shooter. They squeaked in shock and ducked, narrowly avoiding being hit by the bullet which went on to clip someone behind them.

“ _Incendium_!” she shouted, and blue flame enveloped her bat. Before their target could get up and shoot again, Mizar was on them. She swung at their head and the bone shattered, sending blood and charred flesh soaring. She gagged at the sight, but suppressed it.

 _These are murderers_ , she reminded herself. _They murdered children trying to summon a demon and they were going to do it again._

Sniffing, she got up, and felt the presence of someone approaching from behind. She jumped to the side and launched into a spin just as a man ran past her. Her bat collided with his back, sending him flying forward to land on a rock, unconscious. She wiped her brow, and turned to look for her brother.

There he was. Surrounded by at least five bloody heaps that must have previously been cultists, Alcor was crouched over a still-writhing mass, clearly not entertaining the same moral dilemma she was. He was gnawing mercilessly at the figure’s neck – not sucking blood like a vampire, but gnashing his too-sharp teeth indiscriminately until the body seized up and then finally fell limp.

Possibly sensing her presence, he looked up from his feast and locked eyes with her. His pupils were fully blown and the teeth in his too-wide grin were stained with blood. She retched – she knew what she was getting herself into, she knew what kind of life she lived, she knew that her brother was kind and sweet and an annoying dork but right now he was scary as _frick_ and it didn’t matter how many dozens of times she’d seen him like this before, she would still retch and hold back tears and wonder for the briefest of moments why she trusted such a horrible monster, and –

Alcor’s pupils shrank, and his grin flipped into a frown. Worried that he’d somehow heard that last thought, Mizar opened her mouth to speak, and was cut off by a kick to the small of her back. With a yelp, she crumpled over in pain.

“Mizar!” she heard Alcor cry, and she could hear the naked concern in his voice – it sounded so human that she was taken aback.

_That’s your brother, that’s your brother, you know that’s your brother…_

She groaned again as rough arms wrapped around her, binding her arms to her sides. The person pinning her down let out a triumphant laugh, and she rolled her eyes. There was no way some lame cultist could scare her after the way Alcor had just looked at her.

Deftly, she used one of her feet to push the opposite shoe partway off her foot, and then kicked backward, sending the shoe flying. It flew over her head, landing somewhere in the grass ahead of her. She frowned, and tried again, using a socked foot to push her other shoe half way off, and then flicking her leg backwards, with a little less force this time.

The shoe flew up and smacked her assaulter right in the head. They let out a yelp and their hands automatically flew to their head, leaving Mizar’s arms free. She took advantage of this by quickly rolling over and sitting on the cultist’s stomach. Her bat had rolled away, but that didn’t matter, not when she’d spent summers learning how to box from Grunkle Stan. She balled her hand into a fist and raised it into the air, about to initiate a furious pummeling – and then something writhing and black tackled her out of nowhere, sending her tumbling off to the golf cart.

Mizar yelped in surprise, and toppled into the side of the cart. Her head was spinning and she had to take a moment before she could sit up. Before she got the chance to, she found the dark figure sitting on her stomach, preventing her from moving. She snarled and spat right at where she assumed the figure’s face was. A familiar voice called out “ew, gross!”, and her vision finally stopped rushing enough for her to make out her surroundings.

 _Oh, you’ve got to be kidding me_.

It was Alcor. He was still covered in blood, but he had the same worrywart look on his face that he would get all the time before the Transcendence. His wings were fluttering anxiously, and she noticed his claws had mostly retracted. It was like she was looking at a completely different person.

She honestly would have preferred to, at this point.

“Bro-bro, what are you doing?” Mizar shouted.

Alcor’s look of concern did not waver. “Mizar, I was so worried when I saw that guy kick you!”

Mizar groaned, starting to wonder if she was approaching a new record number of groans on a mission. “I know what I’m doing, doofus!” she retorted. “I had him, and now he’s getting away!”

Alcor’s head snapped up, and turned to look at the three figures running frantically away from the twins and toward the cave.

“Oh, shit!” he swore, floating up off of his sister.

She grumbled, and sat up. Getting tackled by a demon somehow hurt more than getting kicked in the back. Sure, he had been trying to protect her, but it was getting really annoying how he thought she couldn’t protect herself too. She looked up at him, and he stared back with impatient eyes and hand extended.

“Grab on, I’ll fly us over to-” he started to say – and then vanished.

Well, vanished wasn’t quite the right word. Mizar could still see him, but he was also pretty clearly not there. The there/not-there Alcor looked surprised for a split second, and then slapped himself in the face.

“Oh, great!” he moaned. “I ran out of time. This is so annoying!” He started pacing in mid-air, waving his hands around dramatically, inadvertently causing fish to fly up and down out of the nearby pond. “It’s going to be so great when I’m strong enough to be physical without needing a deal. Ugh!”

Mizar sighed. “Here,” she said, reaching into her sweater and pulling out a piece of paper with Alcor’s circle inscribed on it. “I’m already bleeding, I’ll just offer you some more blood to stay physical until we finish this job.”

Alcor stopped pacing, and looked for a moment like he was considering the offer. Mizar was about to dab the blood on the circle whether her brother accepted it or not, when suddenly the silence was cut by a pained shriek coming from the direction of the cave.

“There’s no time!” he blurted. “I’m going to need more power right now than a little blood will give me. Let’s do the possession thing!”

Mizar groaned for a record fourth time, and dropped the paper. “Fine. Fine? Fine!” she snapped. “You can possess me to take care of this cult and save the kids.”

Alcor nodded furiously and extended a hand covered in blue flame. “Yeahyeahyeah-” he babbled.

“BUT!” she added, moving her hand away from his. “When we get back, you’re gonna owe me a LOT. You’re gonna- you’re gonna have to… We’re gonna have a long talk about our raiding dynamic, because you’ve really been rustling my jimmies today, okay?”

Alcor frowned, and then winced as another shriek tore through the glen. “Okay, sure! Whatever you want! Let’s just go save those kids!”

Mizar grimaced, and then exhaled. Her brother was being a massive dink, but she swallowed her pride (for now) because the most important thing was stopping those cultists from hurting more children. She grabbed Alcor’s clawed hand, felt the flame run up her arm, and relaxed.

She relaxed as he strengthened his grip on her essence, as he pulled her out of her body to float there in the ether, even as he grabbed her bat and ran off to the cave in her body without waiting for her to catch up. The deal didn’t specify that she had to go with him, and right now she really wasn’t in the mood anyway. There was too much anger welling up inside her brain, and she didn’t like that, didn’t like how it felt, at least not when it was about something that couldn’t easily be kicked or knitted into submission.

All she wanted to do was relax and try to let the serenity of the glen wash away some of that anger. She listened to the forest, to the birds chirping, to the grass bending in the breeze, to the screaming and cackling that started to emanate from the cave. She listened, and she closed her eyes, and she thought about those couple of years in Piedmont, when all the twins had was each other, and they promised to always have each other’s backs.

Some days, it was pretty cool having a demon for a brother. Today was not one of those days.

**Author's Note:**

> This was actually written a year ago, and was supposed to be the first chapter of a longfic that I don't think will ever be finished. I believe it stands pretty well on its own.


End file.
